docs: Add user guide for *Deactivate your account* feature

templates/zerver/help/deactivate-account.md

@@ -0,0 +1,45 @@
+# Deactivate your account
+
+We'd be sorry to see you go, but you can follow the following steps to deactivate your Zulip account.
+
+1. Click the cog (![cog](/static/images/help/cog.png)) in the upper right corner of the right sidebar.
+
+2. Select **Settings** from the dropdown menu that appears.
+
+    ![settings](/static/images/help/settings.png)
+
+3. Upon clicking **Settings**, your view will be replaced with the **Settings** page. Click the red **Deactivate your account** button on the bottom of the **Your account** section.
+
+    ![Deactivate your account button](/static/images/help/deactivate-account.png)
+
+4. After clicking the **Deactivate Account** button, a modal window titled **Deactivate Your Account** will appear.
+
+    ![Deactivate your account modal](/static/images/help/deactivate-modal.png)
+
+5. To confirm the deletion of your account, click the red **Deactivate now** button. Please note that any bots that you maintain will be disabled.
+
+6. After clicking the **Deactivate now** button, you will be logged out and returned to the Zulip login page.
+
+Please note that you cannot register a Zulip account using the email address of a deactivated account. However, you can ask a Zulip realm administrator to reactivate your account.
+
+## Reactivating an account
+
+Zulip realm administrators can choose to reactivate a user's deactivated account by following the following steps.
+
+1. Click the cog (![cog](/static/images/help/cog.png)) in the upper right corner of the right sidebar.
+
+2. Select **Administration** from the dropdown menu that appears.
+
+    ![Administration dropdown](/static/images/help/administration.png)
+
+3. Upon clicking **Administration**, your view will be replaced with the **Administration** page. Click the **Deactivated Users** tab at the top of the panel; it turns gray upon hover.
+
+    ![Administration](/static/images/help/admin-panel.png)
+
+4. In the **Deactivated users** section, click the orange **Reactivate** button to the right of the user account that you want to reactivate.
+
+    ![Deactivated Users](/static/images/help/deactivate-panel.png)
+
+5. After clicking the **Reactivate** button, the button will transform into a red **Deactivate** button, confirming the success of the account's reactivation.
+
+    ![Reactivate success](/static/images/help/reactivate-success.png)

templates/zerver/help/index.md

@@ -39,7 +39,7 @@ as a “**realm**”.
 * [Signing out](/help/signing-out)
 * Find your Zulip organization (not implemented)
 * Set up two-factor authentication (not implemented)
-* Deactivate your account
+* [Deactivate your account](/help/deactivate-account)
 
 ## Messages
 ### Sending